Device for preparing and applying labels and a method of operation thereof

ABSTRACT

A device for preparing and applying labels and a method of operating said device is provided. The device includes three parts: a roller transport track, a label dispenser and a label manipulator. The latter can pick up a label deposited by the label dispenser on the roller transport track and stick it at a predetermined point onto an object arranged in any desired way in a three-dimensional space.

BACKGROUND OF THE INVENTION

The invention relates to a device for preparing and applying labels anda method of operating said device.

Hand-held labeling machines are already known, using which self-adhesivelabels are peeled off from a carrier strip and can be applied to anobject. The carrier strip, on which a large number of labels is appliedone behind another, is pulled off from a roll and, at the point of issueof the label, is led around a peeling edge. The label is transportedfurther in a straight line, so that its gumming is exposed. At the pointof issue of the label, the hand-held machine has transport rollers, withwhich it is rolled over the object to be labeled. In this process, thetransport rollers move the carrier strip further forward, with theresult that the label is completely peeled off from the carrier strip onthe transport path and is rolled onto the object.

Such a hand-held machine is well suited for the application of pricelabels to sales articles in a department store, where large quantitiesof identically inscribed labels have to be applied in an arbitraryposition to objects which are identically shaped in each case. Bycontrast, if individually printed labels have to be appliedautomatically in a defined position to articles that are differentlyshaped in each case, such as is the case, for example, in automatic mailpreparation systems, the known machine cannot be used.

DE-C-38 31 392 has already disclosed a device for the application ofindividually printable labels to workpieces. In the case of this device,a carrier strip having a large number of labels applied thereto onebehind another is used. A label is firstly, together with the carrierstrip, led past a printer. After the printing, the carrier strip is ledpast a removal point and the label is for the most part separated fromthe carrier strip by deflecting the latter around a roll ofcomparatively small diameter. A suction gripper fastened to anindustrial robot engages on the label, projecting freely into space, andremoves said label from the removal point. Installed underneath thelabel projecting into space is a removal plate. The latter is intendedto make it possible for the label to be picked up reliably by thesuction gripper even when the latter has a position tolerance that istypical for such robots, through which the label otherwise would bepressed "downward".

It cannot be seen from DE-C-38 31 392 how in this case the adherence ofthe label to the removal plate is prevented. In addition, since a labelto be removed remains connected to the carrier strip until it is removedcompletely, the following label can only be printed when the previouslabel has been removed.

U.S. Pat. No. 3,428,509 discloses a device for preparing and applyinglabels, in which the latter are peeled off completely from a carrierstrip, pressed firmly with gumming pointing downward onto a transportroller having a rough surface and pushed by the latter onto a removalface in the access region of a label manipulator. Although the removalface is provided with ribs aligned in the transport direction of thelabels, which are intended to prevent the labels from adhering, thisremoval face remains stationary in relation to the label while thelatter is being pushed on, so that the adhesion that is unavoidablypresent of the gumming to the ribs must be overcome by the pushingtransport roller.

SUMMARY OF THE INVENTION

The object of the invention is therefore to specify a device forpreparing and applying labels, and a method of operating said device,which permit reliable removal of a label and allow the printing of afollowing label irrespective of the removal of the preceding label.

The object, insofar as it relates to the device, is achieved by thedevice according to the invention which essentially comprises threesections:

a roller transport track having a multiplicity of shafts that arearranged in one plane, parallel to another, and can be drivensynchronously, on which in each case a plurality of transport rollers isfitted in a rotationally fixed manner,

a label dispenser, which can deposit a single label onto the transportrollers of the roller transport track, and a label manipulator, whichpicks up the label from the roller transport track in a predefinedaccess region of the latter, and sticks said label at a predeterminedpoint onto an object of any shape arranged in a three-dimensional space.

The labels are preferably applied one behind another on a carrier strip,the carrier strip provided with the adhesive labels being unwound from asupply roll, led around a peeling edge at an acute angle and, after theissuing of the labels, is wound up onto a wind-up roll. The peeling edgeis in this case arranged at the input side on the roller transporttrack, so that a label peeled off from the transport strip is pushedonto the roller transport track. In this case, the transporting speedsof the carrier strip and of the roller transport track are equal. Thepeeled-off label then lies with its gumming on the transport rollers ofthe roller transport track. In order to avoid the label adhering to thetransport rollers, the latter have a very small contact area with thelabel. This is achieved by the rollers being designed as pin-wheels orelse as narrow Teflon disks. There is a particularly low adhesion forcebetween this material and the gumming of the label.

Fitted to the roller transport track is a sensor, which signals thearrival of a label in the access region of the label dispenser, afterwhich the controller of the device switches off the drive of the rollertransport track. In a preferred embodiment of the invention, the labeldispenser is a label printer, which operates in accordance with one ofthe known printing processes. Preferably, however, the label printeroperates in accordance with the thermal printing process, and the labelsare composed of thermal printing paper. It is particularly advantageoushere to use thermal printing paper which colors red at a first printinghead temperature and black at a second, higher temperature.

The label manipulator contains, as the essential component, anelastically compressible foam cushion made of a closed-cell foammaterial, through which the suction duct is led. The latter is connectedto a vacuum pump. Using the face through which the suction duct emerges,the foam cushion can be placed over the full face onto a label locatedin the access region of the label dispenser. In the case of a preferreddesign, the foam cushion is adhesively bonded to a pressure plate,through which the suction duct is led. The pressure plate is held on asupporting plate such that it can be displaced parallel to itself alongits surface normal, and is supported against said supporting plate by acompression spring. Depending on the size of the label, the labelmanipulator may also contain more than one pressure plate. The suckingup of the label onto the foam cushion or cushions is performedparticularly reliably if the axes of the suction ducts of all the foamcushions are aligned radially with respect to a shaft of the rollertransport track, which is located remote from the label edges in thecentral region of the label. At the same time, the axes of the suctionducts advantageously point toward the center of the space between twoadjacent transport rollers located on this shaft, whose spacingcorresponds to the diameter of the suction duct.

The label manipulator is fastened on a robot arm, which can move betweenthe label dispenser and a transport track, running perpendicular to itsmovement track, of an object to be labeled. At the same time, the labelmanipulator can have its height adjusted by the robot arm and can berotated about a vertical axis.

A labeling operation using the device previously described, which isadditionally further equipped with a measuring device for the locationand the dimensions of an object to be labeled, proceeds in the followingmanner:

Firstly, the location and the dimensions of the object to be labeled aremeasured. A label to be applied to the object is then issued by thelabel dispenser and provided on the roller transport track in the accessregion of the label dispenser. A negative pressure is now generated inthe suction duct or ducts of the label manipulator and at the same timethe label manipulator is lowered onto the label located in the accessregion, where said label is sucked up onto the foam cushion or cushions.

The label manipulator is now moved over the point of application of thelabel on the object and rotated about its longitudinal axis until thealignment of the label corresponds to its desired angular position onthe object. The label manipulator is then lowered and, as a result, thelabel is pressed onto the object. The pressing force with which thistakes place is determined here by the force of the compressionspring(s). The foam cushion or cushions and, therewith, the label wrapsaround irregularities of the object. After a predefined period of time,the vacuum pump is switched off, the label manipulator is lifted andmoved back to the roller transport track.

A particularly critical method step in the method described above isrepresented by the lifting of the label from the roller transport track,since the foam cushion must be placed onto the label with a certain butminimum pressure in order to suck up the label reliably. As a result,the label may adhere to the transport rollers. As has already beendescribed, although the adhesion force is kept small by the specialconfiguration of the transport rollers, it can be reduced still furtherin a development of the invention by the transport rollers being setrotating slowly during the sucking up and lifting of the label.

Further features, advantages and developments of the invention can betaken from the subclaims and the description and drawing of an exemplaryembodiment that is described below.

BRIEF DESCRIPTION OF THE DRAWING

In the drawing:

FIG. 1 illustrates a device for preparing and applying labels in aschematic illustration,

FIG. 2 illustrates a label dispenser, designed as a label printer, in aschematic side view,

FIG. 3 illustrates a label manipulator in front and side view in itsthree-dimensional assignment to a roller transport track illustrated inplan view.

It should be understood that the drawings are not necessarily to scaleand that the embodiments are sometimes illustrated by graphic symbols,phantom lines, diagrammatic representations and fragmentary views. Incertain instances, details which are not necessary for an understandingof the present invention or which render other details difficult toperceive may have been omitted. It should be understood, of course, thatthe invention is not necessarily limited to the particular embodimentsillustrated herein.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

FIG. 1 illustrates a device 10 for preparing and applying labels in aschematic illustration. Said device comprises a label dispenser 12having an access region 14 for a label manipulator 16. The labelmanipulated 16 is fitted on a robot arm 18. The robot arm 18 can bemoved along a guide rail 20 in the direction of the double arrow X. Inaddition, the robot arm 18 can be lifted and lowered in the direction ofthe double arrow Z, and rotated about its longitudinal axis in thedirection of the double arrow R.

The guide rail 20 extends from the access region 14 as far as atransport track or conveyor 22 running perpendicularly to it, on which asupporting surface 24 for an object 26 to be labeled can be displaced inthe direction of the arrows Y.

Located above the transport track 22 is a video camera 28, which canrecord the entire surface of the supporting surface 24. The video cameraor measuring device 28 is connected to a controller, which can ascertainfrom the video signals the dimensions of the object 26 as well as itslocation on the supporting surface. Depending on this information, therobot arm 18 and the position of the supporting surface 24 on thetransport track 22 can be controlled. The controller 100 is alsoconnected to a drive mechanism 101 for rotating the shafts 54 of thetrack 50. The controller 100 is also connected to the light sensor 74 asindicated schematically in FIG. 3. The label manipulator 16 is connectedto a vacuum pump 32 via a negative-pressure or suction line 30.

In FIG. 2, the label dispenser 12 is illustrated in a schematic sideview. It is designed as a label printer 34. Rotatably mounted in theupper region of the printer frame 36 is a supply roll 38, on which acarrier strip 40 for a multiplicity of self-adhesive labels 48, arrangedone behind another, is rolled up. The end of the carrier strip 40running off the supply roll 38 is led between a thermal printing bar 42and a printing roll 44 in such a way that the label to be printed facesthe thermal printing bar 42. Arranged downstream of the thermal printingbar 42 in the transport direction is a peeling bar having a peeling edge46, around which the carrier strip 40 is led at an acute angle. As aresult, the printed label 48 is peeled off the carrier strip 40 andpushed onto a roller transport track 50. In the exemplary embodimentillustrated in FIG. 2, the roller transport track 50 comprises a numberof pin-wheels 52, which are fitted in a rotationally fixed manner on sixshafts 54 arranged in one plane, parallel to one another. The printingroll 44 and the pin-wheels 52 are driven at a synchronouscircumferential speed.

The end of the carrier strip 40 freed from the labels 48 is rolled up ona wind-up roll 56. The diameter of the supply roll 38, which is ameasure of the number of labels still available, is monitored by asensing lever 58 sensing the circumference of the supply roll 38. Assoon as a switch flag 60 fitted to the latter comes out of a forkedlight barrier 62, the end of the carrier strip 40 is signaled to thecontroller, which for its part stops the device 10.

FIG. 3 illustrates the label manipulator 16 in front view at a and inside view at b. FIG. 3 also illustrates the three-dimensionalassociation between the manipulator 16 and a roller transport track 50'illustrated in plan view. The track 50' differs from the rollertransport track 50 only in the fact that the transport rollers 70 aredesigned as narrow Teflon disks, whose line of contact 72 with a label48 is like a burr. The transport rollers 70, 70' of adjacent transportshafts 54 are offset with respect to one another such that the transportrollers 70 of the one shaft project into a gap between adjacenttransport rollers 70' of the other shaft. In this case, the spacing ofthe shafts 54 is only slightly greater than half the diameter of thetransport rollers 70, 70'.

The access region 14 of the label dispenser 12 on the roller transporttrack 50' is symbolized by a label 48 resting on the latter. Said labelcovers three shafts 54a, 54b, 54c. The arrangement of the transportrollers 70b on the shaft 54b will be discussed further in conjunctionwith the description of the label manipulator 16.

The label manipulator 16 is illustrated in a partially sectioned frontview in FIG. 3a and in a partially sectioned side view in FIG. 3b. Itcomprises a supporting plate 80, which is fastened on the robot arm 18.On its right-hand side in the figure, it is penetrated by two guideholes 82, and on the left-hand side by two guide holes 82'. Displaceablymounted in the latter are guide pins 84 and 84', to whose lower end apressure plate 86 or 86' is fastened. The upper end is in each casesecured by a securing ring 88 against sliding out of the supportingplate 80. Pushed onto each guide pin 84, 84' is a helical compressionspring 90, which is supported on one side by the supporting plate 80 andon the other side by the pressure plate 86, 86'.

On the side of the pressure plate 86, 86' facing the roller transporttrack 50', a cuboidal elastically compressible foam cushion 92, 92' madeof a closed-cell foamed material is adhesively bonded over the fullface. Each foam cushion is penetrated by a suction duct 94 that iscircular in cross section, is expanded downward like a funnel and at thetop is led through the pressure plate 86 or 86', where it ends at itsupper side in a hose nipple 96. A negative-pressure line 30 can bepushed onto each hose nipple (FIG. 1).

The suction ducts 94 of the foam cushions 92, 92' are arranged radiallyabove the shaft 54b of the roller transport track 50'. Each suction ductin this case ends above a transport roller pair 70b, whose spacing dcorresponds to the diameter of the suction duct 94.

This arrangement has the advantage that the label 48 is well supportedin the active region of the suction ducts 94. The label is therefore notdeformed in this region by the pressure of the foam cushion 92, 92'placed on it, which deformation would lead to a reduction in the suctioneffect of the vacuum pump 32.

The operation of providing a label in the access region 14 of the rollertransport rack 50' and the lifting of the label 48 will be describedbelow. The label is peeled off the carrier strip 40 at the peeling edge46, and passes onto the transport rollers 70, 70' and 70b, from which itis transported as far as a reflection light barrier 74 which, for itspart, switches off the drive of the shafts 54. At this time, the label48 is located in the access region 14 of the label dispenser 12. Thelatter is now lowered onto the label 48 until the lower face 93 of thefoam cushions 92, 92' lie with the full face on the label 48 and areslightly compressed under the placing pressure. As a result, theairtight sealing of the suction ducts 94 by the label is ensured. Saidlabel is sucked up and, since the transport rollers 70 are rotated at alow circumferential speed during the placement of the foam cushions 92,92', as well as during the sucking up and lifting of the label, isreliably lifted from the transport rollers 70. The next label can beprinted as soon as the label 48 has been deposited on the rollertransport track 50, 50'.

From the above description, it is apparent that the objects of thepresent invention have been achieved. While only certain embodimentshave been set forth, alternative embodiments and various modificationswill be apparent from the above description to those skilled in the art.These and other alternatives are considered equivalents and within thespirit and scope of the present invention.

What is claimed is:
 1. A device for preparing and applying labels, thedevice comprising:a label dispenser comprising a label printer fordispensing a label to roller transport track, the track extending fromthe printer through an access region, the track comprising a pluralityof coplanar and parallel shafts that can be driven synchronously, eachshaft passing through and being rotationally fixed to at least onetransport rollers, the device further comprising a label manipulator forengaging the label in the access region and transporting the label fromthe access region to a predetermined point on an object, the manipulatorcomprising a face for engaging the label, the face comprising a suctionduct, the shafts and rollers of the track capable of being driven toconvey the label to the access region and during sucking engagement ofthe label by the label manipulator.
 2. The device of claim 1 wherein theshafts are spaced apart by a distance, the rollers having a diameter,the distance being greater than one-half of the diameter of the rollers.3. The device of claim 1 wherein the rollers staggered with respect toeach other.
 4. The device of claim 1 wherein the rollers comprisepin-wheels.
 5. The device of claim 1 wherein the rollers comprise disksfabricated from polytetrafluoroethylene.
 6. The device of claim 1wherein the dispenser further comprises a peeling edge disposed betweenthe track and the printer for peeling a label having adhesive coatedonto one side thereof off of a carrier strip, the label being pushed bythe peeling edge onto the track with the adhesive-coated side engagingthe track.
 7. The device of claim 6 wherein the carrier strip is guidedpast the printer and around the peeling edge at a first transport speed,the rollers of the track being rotated at a second transport speed, thefirst and second transport speeds being equal.
 8. The device of claim 1further comprising a sensor for sensing the arrival of a label in theaccess region and for sending an arrival signal to a controller, thedevice further comprising a drive mechanism for rotating the shafts ofthe track, the controller being linked to the sensor and the drivemechanism, the controller sending a stop signal to the drive mechanismwhen it receives an arrival signal from the sensor.
 9. The device ofclaim 1 wherein the suction duct is connected to a vacuum pump.
 10. Thedevice of claim 1 wherein the face of the manipulator is disposed on alower side of an elastically compressible foam cushion fabricated from aclosed-cell foam material.
 11. The device of claim 10 wherein the foamcushion further comprises an upper side that is connected to a pressureplate, the suction duct passing through the foam cushion and thepressure plate.
 12. The device of claim 11 wherein the pressure plate isslidably connected to a supporting plate by at least one guide pin, thepressure plate being biased away from the supporting plate by at leastone spring.
 13. The device of claim 11 wherein the manipulator furthercomprises a plurality of foam cushions, each foam cushion being slidablyconnected to a common supporting plate by at least one guide pin, eachpressure plate being biased away from the supporting plate by at leastone spring.
 14. The device of claim 1 wherein the access region isdisposed above a central shaft of the track that passes centrallythrough the access region and said central shaft passes through tworollers that are spaced apart by a spacing distance,the suction ducthaving a diameter, the diameter of the suction duct being about equal tothe spacing distance between the two rollers of the central shaft, asthe manipulator is lowered onto the access region, the suction duct isdisposed in alignment with said central shaft and between the two spacedapart rollers of the central shaft.
 15. The device of claim 1 whereinthe access region is disposed over three shafts of the track, thesuction duct being aligned with one of the shafts in this region whenthe face of the manipulator engages a label.
 16. The device of claim 1wherein the manipulator is connected to a robot arm, the arm beingmounted to sliding movement on a guide rail between the dispenser and atransport conveyor which extends perpendicular to the guide rail andwhich carries the object to be labeled, the arm being adjustable inheight for purposes of raising and lowering the manipulator and the armbeing rotatable about a vertical axis.
 17. The device of claim 1 furthercomprising a measuring device for measuring the location and planardimensions of the object to be labeled.
 18. A device for preparing andapplying labels, the device comprising:a label dispenser comprising alabel printer for dispensing a label to roller transport track, thetrack extending from the printer and an access region, the dispenserfurther comprising a carrier strip which accommodates a plurality ofspaced-apart and aligned self-adhesive labels each having anadhesive-coated side that engages the carrier strip, the dispenserfurther comprising a peeling edge disposed between the track and theprinter, the carrier strip being guided past the printer and around thepeeling edge at an acute angle whereby the label is peeled off thecarrier strip and pushed onto the track with the adhesive-coated sideengaging the track, the track comprising a plurality of coplanar andparallel shafts that can be driven synchronously, each shaft passingthrough at least one transport rollers, the dispenser further comprisinga sensor for sensing the arrival of a label in the access region and forsending an arrival signal to a controller, the device further comprisinga drive mechanism for rotating the shafts of the track, the controllerbeing linked to the sensor and the drive mechanism, the controllersending a stop signal to the drive mechanism when it receives an arrivalsignal from the sensor, the device further comprising a labelmanipulator for engaging the label in the access region and transportingthe label from the access region to a predetermined point on an object,the manipulator comprising a face for engaging the label, the facecomprising a suction duct that is in communication with a vacuum pump,the access region being disposed above a central shaft of the track thatpasses centrally through the access region and said central shaft passesthrough two rollers that are spaced apart by a spacing distance, thesuction duct having a diameter, the diameter of the suction duct beingabout equal to the spacing distance between the two rollers of thecentral shaft, as the manipulator is lowered onto the access region, thesuction duct is disposed in alignment with said central shaft andbetween the two spaced apart rollers of the central shaft.
 19. Thedevice of claim 18 wherein the shafts are spaced apart by a distance,the rollers having a diameter, the distance being greater than one-halfof the diameter of the rollers.
 20. The device of claim 18 wherein therollers staggered with respect to each other.
 21. The device of claim 18wherein the carrier strip is guided past the printer and around thepeeling edge at a first transport speed, the rollers of the track beingrotated at a second transport speed, the first and second transportspeeds being equal.
 22. The device of claim 18 wherein the face of themanipulator is disposed on a lower side of an elastically compressiblefoam cushion fabricated from a closed-cell foam material,the foamcushion further comprises an upper side that is connected to a pressureplate, the suction duct passing through the foam cushion and thepressure plate, the pressure plate is slidably connected to a supportingplate by at least one guide pin, the pressure plate being biased awayfrom the supporting plate by at least one spring.
 23. The device ofclaim 22 wherein the manipulator further comprises a plurality of foamcushions, each foam cushion being slidably connected to a commonsupporting plate by at least one guide pin, each pressure plate beingbiased away from the supporting plate by at least one spring.
 24. Thedevice of claim 18 wherein the manipulator is connected to a robot arm,the arm being mounted to sliding movement on a guide rail between thedispenser and a transport conveyor which extends perpendicular to theguide rail and which carries the object to be labeled, the arm beingadjustable in height for purposes of raising and lowering themanipulator and the arm being rotatable about a vertical axis.
 25. Thedevice of claim 18 further comprising a measuring device for measuringthe location and planar dimensions of the object to be labeled andtransmitting a location signal indicating the locating and thickness tothe controller.
 26. A method of placing a label on a predetermined pointon an object, the method comprising the following steps:measuring thelocation of the predetermined point on the object to be labeled with ameasuring device, providing a label to be applied to the object in anaccess region of a label dispenser, the label dispenser comprising alabel printer for dispensing a label to roller transport track, thetrack extending from the printer through the access region, the trackcomprising a plurality of coplanar and parallel shafts that can berotated synchronously, each shaft passing through and being rotationallyfixed to at least one transport roller, lowering a label manipulator,the manipulator comprising a face for engaging the label, the facecomprising a suction duct that is in communication with a vacuum pump,rotating the transport rollers in a transport direction directed awayfrom the label dispenser, switching on the vacuum pump and, during saidrotation of the transport rollers, sucking up the label to the face ofthe manipulator, lifting the label manipulator upward, moving themanipulator towards the object, positioning the manipulator and labelover the predetermined point on the object, lowering the labelmanipulator and pressing the label onto the object, switching off thevacuum pump, lifting the label manipulator and moving the back the labeldispenser.